Electrostatic charge sensitive ends down detecting apparatus and method

ABSTRACT

AN APPARATUS AND METHOD FOR DETECTING AND REGISTERING THE EXISTENCE OF ENDS DOWN ON A TEXTILE YARN FORMING MACHINE SUCH AS A SPINNING MACHINE WHEREIN A DETECTOR MOUNTED ON AND MOVABLE WITH A TRAVELING MACHINE TENDER SCANS ELEMENTS WHICH ARE ELECTROSTICALLY CHARGED BY THE FORMATION OF ENDS OF YARN, THE DETECTOR MEANS BEING RESPONSIVE TO VARIATINS IN ELECTROSTATIC CHARGES AND SENSING SUCH CHARGES AS INDICATIVE OF THE ABSENCE AND PRESENCE OF YARNS FORMED BY THE MACHINE.

Nov. 30, 1971 w. 1.. MULLIGAN 3,623,310

HIJI'J'C'l'HOS'l'ATIC CHARGE SENSITIVE ENDS DOWN DETECTING APPARATUS AND METHOD biLed Muy 2b, [-070 2 Shoots-Sheet 1 jlw #7 llllllllllll llllllllllllllllflllllllllll INVENTOR.

WILLIAM L. MULLIGAN ATTORNEYS Nov. 30, 1971 w. L. MULLIGAN ELECTROSTATIC CHARGE SENSITIVE ENDS LOWN DETECTING APPARATUS AND METHOD 2 Sheets-Sheet 3 Filed May 25, 1970 mvmron: W\ LLIAM L. MULLIGAN ATTORNEYS United States Patent 3,623,310 ELECTROSTATIC CHARGE SENSITIVE ENDS DOWN DETECTING APPARATUS AND METHOD William L. Mulligan, Charlotte, N.C., assignor to Parks-Cramer Company, Fitchburg, Mass. Filed May 25, 1970, Ser. No. 41,136 Int. Cl. D01h 13/14, 13/16, 13/26 US. Cl. 57-34 9 Claims ABSTRACT OF THE DISCLOSURE This invention is related to inventions disclosed and claimed in applications entitled Apparatus and Method for Detecting, Piecing up and Reporting Ends Down on Spinning Machines filed June 24, 1968 under Ser. No. 739,462 and now United States Patent 3,486,319; Apparatus and Method for Detecting and Reporting Ends Down on Textile Machines filed Jan. 29, 1969 under Ser. No. 794,880, now United States Patent 3,523,413; and Electric Circuit Means for Textile Strand Ends Down Detecting Apparatus filed Oct. 14, 1964 under Ser. No. 866,265, now abandoned; all owned in common with the present subject invention.

It has previously been proposed that the efficiency of textile machine operators, and particularly of spinners working in the spinning room of a textile mill, may be improved by providing apparatus including a detector mounted on or traveling with a traveling machine tending unit such as a pneumatic cleaner, for patrolling textile yarn forming machine as the traveling unit traverses the same and for-providing an indication which may be consulted by a spinner in order to determine those textile machines or sides of machines in need of correction of improper conditions, that is, in need of the putting up of ends down on the machines. Such apparatus and components of circuitry therefor are the subject matter of the aforementioned related applications.

It has been found that certain elements of a textile yarn forming machine, such as the ends of yarn being formed on a conventional ring spinning frame, are electrostatically charged by friction during the formation of ends of yarn and consequently there is at least a reduction in the charge appearing at a spindle or machine location when an end is down. Moreover, it has been found that such electrostatic charge variation among machine locations may be detected.

With the foregoing in mind, it is an object of the pres ent invention to utilize the electrostatic charge of certain elements of a textile yarn forming machine and variations therein as a means for detecting ends down. In realizing this object of the present invention, an electrostatic charge sensitive detector means is mounted on or carried by a traveling patrolling device, preferably a traveling pneumatic cleaner, and positioned to scan machine elements at each of a plurality of yarn forming locations where electrostatic charges are generated by the formation of yarns at those locations, and whereby the detector means senses variations in the charge at said locations to indicate the absence and presence of yarns.

Some of the objects and advantages of the invention "ice having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIG. 1 is a side elevation of a textile yarn forming machine and a traveling unit incorporating charge responsive detector means in accordance with the present invention;

FIG. 2 is an end elevation, in partial section, of the textile yarn forming machine, traveling unit and charge responsive detector means of FIG. 1;

FIG. 3 is an enlarged perspective view of a detector head portion of the apparatus of FIGS. 1 and 2;

FIG. 4 is an elevation, in partial section, through the detector head of FIG. 3, taken generally as indicated by the line 4-4 in FIG. 3; and

FIG. 5 is a schematic circuit diagram of circuitry used in conjunction With the structure of FIGS. 14.

Referring now more particularly to the drawings, the apparatus of the present invention is there disclosed in operating relation to a textile yarn forming machine, namely a ring spinning machine 10. While only a single spinning frame 10 is illustrated, it is to be understood that machine 10 may be one of a substantial number of spinning machines arranged in rows in a spinning room, in patterns which are substantially conventional. A traveling unit or patrolling device, here illustrated as a pneumatic cleaner 20, is supported above the textile machine 10 for traversing the same along a predetermined path of travel. The specific apparatus chosen for illustration in the drawings is substantially identical to the fourth embodiment of the traveling pneumatic cleaner disclosed in United States Pat. No. 3,304,571, issued on Feb. 21, 1967, and owned in common with the present invention, but it must be understood at the outset that a Wide variety of other patrolling devices are contemplated as useful in the combination of this invention and that the invention is accordingly not to be limited solely to pneumatic cleaners.

The traveling cleaner 20 is supported for movement along a track 21 extending above the spinning frame 10 and includes blowing and sucking air sleeves 22, 23 and 24 depending on either side of the spinning frame 10' from a main fan housing, for removing lint and the like from the spinning frame 10 and the floor by currents of air. As is disclosed more fully in the aforementioned patent directed to the cleaner structure, drive means and a fan are provided for inducing the flow of currents of air for such cleaning. While the traveling pneumatic cleaner 20 may be arranged to traverse a plurality of textile machines such as the spinning frame 10, the present invention contemplates also that the traveling pneumatic cleaner 20 or that the manner in which the cleaner is supported and arranged for traversing a textile machine may be changed in varying ways, including limiting the path of travel of the cleaner to traversal of a single machine only.

Conventional ring spinning frames in wide use in the textile industry of the world at the present time include a creel portion wherein a plurality of bobbins of roving R are suspended, drafting systems D to which the roving is supplied, and spindles equipped with bobbins on which spun yarn S is wound. In spinning the yarn S in conventional manner and packaging the yarn onto bobbins mounted on the spindles of the spinning machine 10, roving passes through the drafting systems D to spinning rings 11 encircling each of the plurality of spindles driven in rotation from the center shaft or tape drum of the machine. On each of the spinning rings 11 is mounted a traveler 12, which with the yarn S moves rapidly around the spinning ring 11 in a well known manner.

Such processing of the roving R into yarn S has now been found to give rise to an electrostatic charge on elements on the machine 10, and particularly on the yarns being formed. The presence of such a charge is particularly pronounced at the balloon of yarn between a traveler 12 and a pigtail guide 14 thereabove. Upon occurrence of an improper operating condition of the textile machine 10, and specifically upon interruption of spinning of the yarn S, the processing of roving cases at the corresponding machine location, and the generation of an electrostatic charge is interrupted. Thus, a charge differential will exist between a balloon of yarn in motion about a spindle and a spindle or machine location at which an end is down. Inasmuch as the spinning machine is provided with a plurality of yarn forming locations, each of which normally processes roving into yarn, a charge differential between adjacent yarn forming locations is indicative of the absence of a yarn being formed at the location of lower or no charge. In the terminology of spinners, the absence of an end of yarn from a yarn forming location is termed an end down.

In order to determine the ends down condition of a textile yarn forming machine such as the spinning machine 10, the present invention provides a detector means carried by and traveling with the cleaner for scanning the yarn forming machine elements upon traversal of the spinning location by the cleaner 20. Preferably, the detector means is so positioned as to traverse that portion of a spinning frame wherein yarns being formed are normally ballooned between a traveler and an overlying guide.

More particularly, in the illustrated embodiment, the detcetor means comprises a detector head 30, having a housing 31 which encloses an electrostatic charge sensing element or plate 32 and an electrical potential detecting device 34. In the form illustrated, the detecting device 34 is a vacuum tube of the twin triode type having the sensing plate 32 connected to one grid thereof but otherwise electrically floating by being neither grounded nor charged. The detector head is mounted from a traveling unit for movement therewith as disclosed in the second filed of the aforementioned related applications, from which such disclosure is herein incorporated. As disclosed more fully hereinafter, the sensing device is electrically connected to a suitable amplification and registering circuit (not shown in detail but disclosed in the aforementioned related applications, from which such disclosure is herein incorporated) for recording fluctations in electrostatic charges acting on the sensing plate 32 as sensed by the detecting device 34. By reason of the provision of a housing 31, the detector head 30 is somewhat directional and has a predetermined zone of sensitivity. As mounted, this zone of sensitivity is directed toward the traversed machine locations at which charges are anticipated to appear.

As illustrated schematically (FIG. 5), the two triode sections of the vacuum tube disclosed as functioning as the sensing device 34 are connected to provide amplification for fluctuations in the electrical potential of the sensing plate 32 relative to ground. Upon passage of the detector head 30 adjacent a spindle location at which an end of yarn is being formed, the electrostatic charge on the ballooned end of yarn eifects a rise in the electrical potential of the sensing plate 32 relative to electrical ground. Such fluctuation in the potential applied to a first grid 35 of a first section of the vacuum tube results in variation in current flow between the plate 36 and cathode 37 thereof. Such a variation in current flow through the first section of the vacuum tube is coupled to a second section of the vacuum tube and causes the grid 40 thereof to vary current flow between the plate 41 and cathode 42. A sharp fluctuation in the current flow between the plate 41 and cathode 42 of the second section of the vacuum tube is passed through an output 4 capacitor C1, to further amplification and registering circuitry.

In practicing the present invention, a predetermined number of textile yarn forming machines such as the spinning machine 10 are patrolled by the traveling cleaner 20 for the removal of lint or the like therefrom. At the same time, determination of ends down on the machine is accomplished by scanning with the detector head 30 the elements of the machine which are electrostatically charged by the formation of yarns at the spindle locations, such as the balloons of yarn, as the cleaner traverses such locations. By sensing the electrostatic charges on yarns, an indication is derived as to the absence and presence of yarns being formed by the machine 10 at various spindle locations. Such an indication, present as a fluctuation in electrical current derived from or passed by the sensing device 34, is applied to a means responsive to such electrical current for registering the ends down condition of the machine 10.

As the ends down condition is registered, it is contemplated that appropriate means (as disclosed in the aforementioned related applications) will pass a signal upon the number of ends down exceeding a predetermined number established by the mill management as acceptable. The signal passed will then be made available to other elements of a data collecting and display system and may then be used to cause lighting of an annunciator lamp, actuation of a recorder and print out device, or in a wide variety of other ways. Reporting of determined ends down and ends up conditions may also be accomplished continuously or intermittently, as desired.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

I claim:

1. The combination with a textile yarn forming machine having a plurality of yarn forming locations at each of which an electrostatic charge is experienced during the formation of yarn thereat and a drop in such electrostatic charge occurs upon interruption of such yarn formation, such as a spinning machine, of apparatus for detecting the presence and absence of ends of yarn at said machine locations and comprising a traveling unit adapted to travel in a predetermined path of travel along the machine, electrostatic charge sensitive detector means carried by and traveling with said traveling unit for scanning said machine locations upon traversal thereof by said traveling unit, said detector means sensing the electrostatic charge at said machine locations as an indicator of the absence and presence of yarns formed thereat, and means responsive to said detector means for registering the ends down condition of said machine.

2. The combination of claim 1 wherein said detector means comprises an electrostatic charge sensing element and means electrically connected thereto for responding to fluctuation in the electrical potential of said element by signaling the condition of an end normally being formed at a traversed machine location.

3. The combination of claim 2 wherein said detector means is mounted on said traveling unit for passage adjacent said spindle locations.

4. The combination of claim 2 wherein said traveling unit comprises a traveling pneumatic cleaner for removing lint and the like from textile machines traversed thereby by flowing currents of air.

5. A traveling unit movable along a track extending over at least one textile machine such as a spinning machine having a plurality of yarn forming spindle locations and electrostatic charge sensitive detector means mounted on said traveling unit for movement therewith and oriented in a predetermined manner relative thereto for scanning spindle locations of a machine traversed by said traveling means, said detector means sensing the electrostatic charge levels at said spindle location as indicative of the absence and presence of yarns normally being formed thereat.

6. A traveling unit in accordance with claim wherein said detector means comprises an electrically floating sensing element mounted from said traveling unit to pass adjacent said spindle locations and means responsive to variations in the potential of said sensing element for determining the absence of ends of yarn.

7. A traveling unit in accordance with claim 5 and further comprising a fan for inducing a flow of air, drive means for said fan, and air flow distributing means operatively connected with said fan for directing the flow of air induced by said fan for removing lint and the like from textile machines traversed by said traveling unit.

8. A method of patrolling a predetermined number of textile yarn forming machines such as spinning machines having a plurality of yarn forming spindle locations for determining the existence of yarn ends down on the machines comprising the steps of automatically traversing the machines with at least one traveling unit supported on an overhead track extending over the machines and having an electrostatic charge sensitive detector thereon,

and scanning with the detector elements which experience a rise in electrostatic charge level during the formation of yarns at the spindle locations and a drop in such charge level upon interruption of such yarn formation as the traveling unit traverses such locations while sensing the electrostatic charge levels of the elements as indicative of the absence and presence of yarns normally being formed at the spindle locations.

9. A method according to claim 8 wherein the step of traversing the machine includes removing lint and the like therefrom by currents of air induced by a fan included in said traveling unit.

References Cited UNITED STATES PATENTS 3,360,914 1/1968 Black et al. 57--56 3,430,426 3/1969 Bryan et a1. 5734 3,432,877 3/1969 Black et al. 57-56 X 3,486,319 12/1969 Lee et al 57-34 3,523,414 8/1970 Black et al. 5756 DONALD E. WATKINS, Primary Examiner US. Cl. X.R. 5756, 156 

